The purpose of the Television Ophthalmoscope (TVO) Project is to develop an instrument which analyzes television images of the ocular fundus and extracts clinically useful measurements from the images. Further, it is an objective of the project to determine the value of these measurements in specific clinical situations. The Television Ophthalmoscope instrument consists of: (1) A Television and Optical system which views the fundus through a conventional Zeiss fundus camera and creates a television signal; (2) A computer-controlled light source of our design which provides illumination of variable duration and spectral content; (3) A digital computer with specially designed hardware extensions to permit processing of the television images; (4) A set of computer programs to control acquisition and analysis of images; each program is tailored to process a specific class of measurements. Three basic categories of image measurements are under investigation: (1) Quantitative angiography: a series of television frames is scanned after injection of a tracer; these images are automatically analyzed to extract volume flow rates and circulation times; (2) Oximetry: pairs of television images are scanned under illumination at two different wavelengths. The image pairs are processed to determine percent oxygen saturation of the blood in individual retinal vessels; (3) Multispectral reflectance: as many as nineteen images are scanned, each under illumination of a different wavelength range; these images are analyzed to extract reflectance signatures from features of arbitrary shape and orientation.